<!DOCTYPE html>
<!-- This test validates that overlap testing for fixed within an iframe with
overflow hidden either correctly performs overlap testing with an expanded
rect for the fixed content up front (pre-CAP) or invalidates appropriately
so that overlap testing is re-run when the scroll offset updates. Note
that this runs in an iframe to specifically test the case where there is
no paint property scroll node for iframe with overflow: hidden (root will
always have scroll translation and scroll node). If the CAP implementation
ends up changing to include this type of (uncommon) overlap testing,
rebaseline the expected.txt to have the same layer tree structure before
and after the scroll update. -->
<script src="../../resources/run-after-layout-and-paint.js"></script>
<script>
if (window.testRunner && window.internals) {
testRunner.dumpAsText();
testRunner.waitUntilDone();
internals.settings.setPreferCompositingToLCDTextEnabled(true);
}
function runTest() {
runAfterLayoutAndPaint(function() {
if (window.testRunner) {
let dumpText = "Before:\n" + internals.layerTreeAsText(document);
let iframe = document.querySelector('iframe');
let iframeHtmlElem = iframe.contentDocument.documentElement;
iframeHtmlElem.scrollTop = iframeHtmlElem.offsetHeight;
runAfterLayoutAndPaint(function() {
dumpText += "\nAfter scroll:\n" + internals.layerTreeAsText(document);
document.querySelector('pre').textContent = dumpText;
}, true);
}
});
}
</script>
<iframe id="iframe" onload="runTest()" srcdoc="
<style>
html { overflow: hidden; }
.fixed {
position: fixed;
bottom: 20px;
width: 30px;
height: 30px;
background: blue;
}
.tall { height: 1000px; }
.overlapped {
position: relative;
width: 40px;
height: 40px;
background: orange;
z-index: 1;
}
</style>
<body>
<div class='fixed'></div>
<div class='tall'></div>
<div class='overlapped'></div>
"></iframe>
<pre></pre>
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